Mourners listen to a memorial service over a loudspeaker Sunday outside Newtown High School for the victims of the Sandy Hook Elementary School shooting in Newtown, Conn.

President Barack Obama speaks at a vigil on Sunday, for the victims of the Sandy Hook Elementary shooting in the Newtown High School.

A man helps a young girl up the stairs while carrying her backpack as they arrive for services Sunday at Trinity Church in Newtown, Conn.

Angels and a note blessing victims rest on the ground Sunday at the site of a makeshift memorial for school shooting victims at the village of Sandy Hook in Newtown, Conn.

A woman lays flowers at the site of a makeshift memorial Sunday for school shooting victims at the village of Sandy Hook in Newtown, Conn.

A Connecticut State Police tactical team searches the area around St. Rose of Lima Catholic Church while responding to a bomb threat Sunday in Newtown, Conn. Worshippers hurriedly left the church Sunday, not far from where a gunman opened fire Friday inside the Sandy Hook Elementary School in Newtown.

Cheryl Girardi, of Middletown, Conn., kneels beside 26 teddy bears, each representing a victim of the Sandy Hook Elementary School shooting, at a sidewalk memorial Sunday in Newtown, Conn.

Residents wait for the start of an interfaith vigil for the victims of the Sandy Hook Elementary School shooting on Sunday at Newtown High School in Newtown, Conn.

Kayla Hopson and her daughter Lilliana, 9, left, and Janine Caswell and her daughter Genesis, 8, stand wrapped in Red Cross blankets to protect themselves from the cold, rainy weather as they wait in line to attend an interfaith vigil with President Barack Obama on Sunday in Newtown, Conn.

An American flag flies at half staff Sunday outside the Newtown High School before President Barack Obama is scheduled to attend a memorial for the victims of the Sandy Hook Elementary School shooting in Newtown, Conn. A gunman walked into Sandy Hook Elementary School in Newtown Friday and opened fire, killing 26 people, including 20 children.

Mourners listen to a memorial service over a loudspeaker Sunday outside Newtown High School for the victims of the Sandy Hook Elementary School shooting in Newtown, Conn.

Officials prepare to enter a building adjacent to St. Rose of Lima Roman Catholic Church while responding to a bomb threat Sunday in Newtown, Conn. Worshippers hurriedly left the church Sunday, not far from where a gunman opened fire Friday inside the Sandy Hook Elementary School in Newtown.

A personal note from a child is placed on a memorial for the victims of the Sandy Hook Elementary School shooting, Sunday, in Newtown, Conn. A gunman walked into the school Friday and opened fire, killing 26 people, including 20 children.